Dynamics of primitive streak regression controls the fate of neuromesodermal progenitors in the chicken embryo.
Dynamics of primitive streak regression controls the fate of neuromesodermal progenitors in the chicken embryo.
复制标题
原始条纹回归的动力学控制了鸡胚胎中神经抑制祖细胞的命运。
DOI：
10.7554/elife.64819
复制
发表时间：
2021-07-06
期刊：
影响因子：
7.7
通讯作者：
Pourquié O
中科院分区：
文献类型：
--
作者：
Guillot C;Djeffal Y;Michaut A;Rabe B;Pourquié O
在脊椎动物发育的经典描述中，三个胚层的分离在原肠胚形成结束时完成。身体形成，然后进行在一个头到尾的方式，逐步沉积的谱系承诺的祖细胞在退化的原条（PS）和尾芽（TB）。通过回顾性克隆分析的神经中胚层祖细胞（NMPs）的人口，有助于肌肉骨骼前体（近轴中胚层）和脊髓轴形成过程中的识别挑战了这些概念。然而，经典的命运定位研究的PS区在Alpotes迄今未能提供直接的证据，这种双能细胞在单细胞水平。在这里，使用谱系追踪和单细胞RNA测序的鸡胚，我们确定了一个常驻细胞群的前PS上胚层，这有助于神经和中胚层谱系的躯干和尾巴。这些细胞最初表现为经典描述的单能祖细胞，仅在更后部的区域获得双能命运。我们发现，NMPs在轴伸长过程中表现出保守的转录组签名，但在TB中失去了上皮特征。后前梯度的收敛速度和侵入沿着PS导致PS中胚层前体领土的不对称耗尽。通过有限的侵入和增加的增殖，NMP作为构成TB中的主要祖细胞的细胞群被维持和扩增。总之，我们的研究提供了一个新的理解PS和TB的贡献，通过NMPs的身体的胚胎的形成。
In classical descriptions of vertebrate development, the segregation of the three embryonic germ layers completes by the end of gastrulation. Body formation then proceeds in a head to tail fashion by progressive deposition of lineage-committed progenitors during regression of the primitive streak (PS) and tail bud (TB). The identification by retrospective clonal analysis of a population of neuromesodermal progenitors (NMPs) contributing to both musculoskeletal precursors (paraxial mesoderm) and spinal cord during axis formation challenged these notions. However, classical fate mapping studies of the PS region in amniotes have so far failed to provide direct evidence for such bipotential cells at the single-cell level. Here, using lineage tracing and single-cell RNA sequencing in the chicken embryo, we identify a resident cell population of the anterior PS epiblast, which contributes to neural and mesodermal lineages in trunk and tail. These cells initially behave as monopotent progenitors as classically described and only acquire a bipotential fate later, in more posterior regions. We show that NMPs exhibit a conserved transcriptomic signature during axis elongation but lose their epithelial characteristicsin the TB. Posterior to anterior gradients of convergence speed and ingression along the PS lead to asymmetric exhaustion of PS mesodermal precursor territories. Through limited ingression and increased proliferation, NMPs are maintained and amplified as a cell population which constitute the main progenitors in the TB. Together, our studies provide a novel understanding of the PS and TB contribution through the NMPs to the formation of the body of amniote embryos.